U.S. patent application number 13/254341 was filed with the patent office on 2011-12-29 for measuring and checking apparatus.
This patent application is currently assigned to MARPOSS SOCIETA' PER AZIONI. Invention is credited to Maurizio Dalla Casa.
Application Number | 20110314685 13/254341 |
Document ID | / |
Family ID | 41198822 |
Filed Date | 2011-12-29 |
United States Patent
Application |
20110314685 |
Kind Code |
A1 |
Dalla Casa; Maurizio |
December 29, 2011 |
MEASURING AND CHECKING APPARATUS
Abstract
A plug gauge (1) includes a support and protection frame with a
handle (2) that defines a longitudinal axis and houses a position
transducer (25) and electronic devices for wirelessly transmitting
electrical signals indicative of a dimension to be checked. The
gauge also comprises a probe (6) including a mechanical armset (7)
provided with at least one movable feeler (10), and a transmission
mechanism with a stem (17) transmitting movements of the feeler to
the position transducer housed in the handle. The probe is
connected to the handle by means of a quick coupling mechanism (5)
with deformable locking portions (52), the radial arrangement of
which is controlled by a clamping element (60).
Inventors: |
Dalla Casa; Maurizio; (S.
Giovanni in Persiceto (BO), IT) |
Assignee: |
MARPOSS SOCIETA' PER AZIONI
Bentivoglio (BO)
IT
|
Family ID: |
41198822 |
Appl. No.: |
13/254341 |
Filed: |
March 25, 2010 |
PCT Filed: |
March 25, 2010 |
PCT NO: |
PCT/EP10/53945 |
371 Date: |
September 1, 2011 |
Current U.S.
Class: |
33/542 |
Current CPC
Class: |
G01B 5/12 20130101; G01B
3/46 20130101; G01B 2210/58 20130101 |
Class at
Publication: |
33/542 |
International
Class: |
G01B 3/46 20060101
G01B003/46 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 27, 2009 |
IT |
BO2009A000191 |
Claims
1. An apparatus for measuring and checking a mechanical piece
comprising: a support and protection frame with a hollow handle
defining a longitudinal axis; a position transducer with a
stationary part that is housed in the handle and is stationary with
respect to the handle and a movable part that is movable along a
substantially longitudinal direction; a probe, connected to the
support and protection frame, which includes at least one movable
feeler adapted for contacting the mechanical piece to be checked,
and a transmission mechanism having a stem and a transmission
system adapted to transform movements of said movable feeler into
longitudinal movements of the stem, the stem being adapted to
cooperate with the movable part of the position transducer and to
transmit said longitudinal movements to said movable part of the
position transducer; and a coupling mechanism for connecting the
probe to the handle with transversal reference surfaces adapted to
cooperate with reference surfaces of the probe for defining the
longitudinal position of the probe with respect to the handle, said
coupling mechanism being fixed to the support and protection frame
and including locking portions with a modifiable radial arrangement
adapted to cooperate with the probe and a clamping element adapted
to control the radial arrangement of said locking portions for
locking and unlocking the probe to the coupling mechanism.
2. The apparatus for measuring and checking according to claim 1,
wherein said at least one movable feeler is adapted to perform
movements along a transversal direction, the transmission system
being adapted to transform said movements along a transversal
direction of said at least one movable feeler into longitudinal
movements of the stem.
3. The apparatus for measuring and checking according to claim 1,
wherein said locking portions are deformable locking portions.
4. The apparatus for measuring and checking according to claim 3,
wherein the coupling mechanism includes a substantially tubular
base component, which is fixed to the handle and aligned along a
longitudinal direction, and an intermediate element, which is
partly inserted into the base component and includes the deformable
locking portions and the transversal reference surfaces.
5. The apparatus for measuring and checking according to claim 4,
wherein the clamping element includes a threaded ring nut with an
internal threaded portion adapted to cooperate with an external
threaded surface of the base component, the base component
including an internal sloping surface, the intermediate element
including external sloping surfaces and deformable areas of the
locking portions, said internal sloping surfaces and external
sloping surfaces being adapted to mutually cooperate under the
control of a longitudinal thrust which is applied by the threaded
ring nut for causing deformations of said deformable areas and a
consequent change of the radial arrangement of the locking
portions.
6. The apparatus for measuring and checking according to claim 1,
wherein the position transducer is of the inductive type, and the
stationary part includes windings fixedly housed in the handle, the
movable part including a magnetic core which is longitudinally
movable inside the windings, the magnetic core being connected to a
longitudinally movable support adapted to cooperate with said
stem.
7. The apparatus for measuring and checking according to claim 6,
wherein the position transducer comprises a bearing and guide
element which is fixed inside the handle, houses said windings and
comprises an external guide surface adapted to cooperate with
internal surfaces of said movable support for guiding longitudinal
displacements of the movable support.
8. The apparatus for measuring and checking according to claim 1,
including a wireless transmission system for wirelessly
transmitting the electrical signals of the position transducer,
said wireless transmission system comprising at least an emitter
which is connected to said position transducer and housed in the
handle.
9. The apparatus for measuring and checking according to claim 8,
wherein said transmission system is of the radio-frequency type,
and said emitter is an antenna.
Description
TECHNICAL FIELD
[0001] The present invention relates to an apparatus for measuring
and checking a mechanical piece including a support and protection
frame with a hollow handle defining a longitudinal axis, a position
transducer with a stationary part that is stationary with respect
to the handle and a movable part that is movable along a
substantially longitudinal direction, a probe, connected to the
support and protection frame, which includes at least one movable
feeler adapted for contacting the mechanical piece to be checked,
and a transmission mechanism having a stem and a transmission
system adapted to transform movements of the movable feeler into
longitudinal movements of the stem, the stem being adapted to
cooperate with the movable part of the position transducer and to
transmit the longitudinal movements to the movable part of the
position transducer; and a coupling mechanism for connecting the
probe to the handle with transversal reference surfaces adapted to
cooperate with reference surfaces of the probe for defining the
longitudinal position of the probe with respect to the handle.
BACKGROUND ART
[0002] Checking apparatuses, for example the so-called "plug
gauges", for checking dimensions and shape of mechanical pieces are
known.
[0003] The U.S. Pat. No. 4,348,814 discloses examples of such
gauges, wherein a measuring armset connected to a support element
includes two feelers that are fixed to movable arms at
diametrically opposed positions for touching the surface of a hole
to be checked.
[0004] A transducer detects mutual movements of the movable arms
and provides, by means of cable wires, external processing and
display devices with electrical signals indicative of the mutual
position of the feelers.
[0005] Wireless plug gauges are also known, wherein the signals
indicative of the dimension to be checked and generated by the
transducer are wirelessly sent to external units for being
processed and displayed.
[0006] The known plug gauges can be manually operated and typically
include a support and protection frame with a handle that has an
external surface serving as gripping for an operator's hand and a
probe including mechanical devices for detecting the hole
dimensions. The probe can be disengaged from the main body in order
to be replaced by another probe depending on the checking to be
carried out, for example depending on the nominal diameter of the
hole to be checked.
[0007] The U.S. Pat. No. 4,571,839 discloses an example of such
manual plug gauges including a probe that can be disengaged and
replaced. The illustrated plug gauge is provided with a cable power
supply and a cable transmission of the measure, and the probe is
connected to a hollow support and protection frame serving as
handle. The probe, which includes a measuring cell with a
transducer, is connected to the hollow tubular frame by means of a
mechanical coupling consisting of a radial screw that passes
through a through bore located in the tubular frame and engages a
circular groove located in the probe.
[0008] Inside the handle there are electrical cables of the
transducer that are coupled to external electrical cables by means
of corresponding connectors for enabling the transmission of
signals and the power supply.
[0009] The plug gauge disclosed in U.S. Pat. No. 4,571,839 ensures
flexibility in use thanks to the possibility of replacing the probe
depending on the checking to be performed. However, such a
replacing operation is not quite easy owing to the adopted coupling
system and the arrangement of the electrical connectors that are
hard to reach. The probes alternatively used in the plug gauge
according to U.S. Pat. No. 4,571,839 each include, as stated, a
measuring cell that comprises, in addition to the transducer,
feelers and an armset for transmitting to the transducer the
movements of the feelers. The probes to be used to fit the gauge to
different nominal dimensions are thus rather complex and expensive.
Moreover, in the event of breakage of just the mechanical part or
just the electrical part of the probe, it is necessary to replace
the whole probe or at least the whole measuring cell. The
international patent applications published under Nos.
WO-A-2007/128805 and WO-A-2008/049862 disclose some types of plug
gauges that are provided with wireless transmission of signals and
have replaceable probes. According to some embodiments of
publication WO-A-2007/128805, each probe includes the feelers and a
mechanical transmission system, while another intermediate element
between the probe and the handle, or interface, includes the
transducer and the electrical connector. Probes, interface and
handle are connected by means of threaded couplings, and, even
though the system provides advantages in terms of flexibility of
use, the replacing operations for fitting specific nominal
dimensions to be checked require a not negligible amount of skill
and time. Moreover, the longitudinal dimensions of the gauge can
not be smaller than a limit value which could be too great for
certain applications.
DISCLOSURE OF THE INVENTION
[0010] Object of the present invention is to provide gauges of the
modularized type that improve the features of the known gauges in
terms of flexibility, convenience and compactness, and enable to
reduce costs and time for fitting different measuring ranges and/or
different kinds of checking.
[0011] This and other objects are achieved by an apparatus
according to claim 1.
[0012] An apparatus for measuring and checking mechanical pieces
according to the present invention includes a support and
protection frame with a hollow handle that defines a longitudinal
axis and houses a position transducer having a stationary part and
a movable part which is movable along a substantially longitudinal
direction. A probe, with at least one movable feeler and a
transmission mechanism for transforming movements of the feeler
into longitudinal movements of a stem, is connected to the support
and protection frame by means of a quick coupling mechanism. The
quick coupling mechanism is fixed to the handle and includes
transversal reference and abutment surfaces for the probe defining
a longitudinal operative position of the latter and locking
portions. The radial arrangement of the locking portions,
preferably deformable, is controlled by means of a clamping
element, for example a ring nut coaxial with the longitudinal axis,
for locking and unlocking the probe.
[0013] Preferably, the position transducer is of the inductive
type, and a bearing and guide element houses stationary windings
inside of which a magnetic core fixed to an associated support
element can longitudinally slide. By virtue of the transmission
mechanism, displacements of the probe feeler cause such support
element to move, guided by external surfaces of the bearing and
guide element. In a preferred embodiment, the feeler of the probe
can transversally displace.
[0014] In an apparatus according to the present invention, the
number of the component parts is advantageously optimized for
ensuring a remarkable ease and flexibility of use while maintaining
operation reliability and accuracy, reducing production and
management costs, and enabling to have a particularly compact
structure with reduced overall dimensions.
[0015] Moreover, the combination of the above-described coupling
mechanism and the wireless transmission system, according to the
preferred embodiment of the invention, ensures a particular
flexibility of use and ease in retooling and handling component
parts that can be replaced in a very simple and rapid way.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention is now described in detail with reference to
the enclosed sheets of drawings, given by way of non-limiting
example, wherein:
[0017] FIG. 1 is a perspective view of a gauge, more specifically a
plug gauge, according to the invention with some parts removed for
the sake of simplicity;
[0018] FIG. 2 is a perspective exploded view of the plug gauge of
FIG. 1, taken from a different point of view and shown on a
different scale with respect to FIG. 1;
[0019] FIG. 3 is a perspective, longitudinally sectioned view of
the plug gauge of FIG. 1;
[0020] FIG. 4 is an enlarged view of a part of FIG. 3, wherein a
feeler is additionally shown;
[0021] FIG. 5 is a perspective, exploded, sectioned and enlarged
view of some component parts of a coupling mechanism of the plug
gauge shown in the previous figures; and
[0022] FIGS. 6A, 6B and 6C are perspective, partial and
longitudinally sectioned view of different gauges according to the
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0023] The figures show a measuring and checking apparatus, more
specifically an electric gauge for manually checking linear
dimensions of a mechanical piece, according to the present
invention. In the embodiment of FIGS. 1 to 5 such gauge is a plug
gauge 1, for checking internal diametral dimensions, provided with
a wireless transmission of measuring signals. The plug gauge 1
includes a support and protection frame with a hollow handle 2 that
defines a longitudinal axis and is shaped in such a way that its
central portion has ergonomic shape for the manual use of the
gauge. The handle 2 has a control push button 3 for enabling an
operator to manually select the required function of the gauge 1,
such as, for example, switching on or switching off the gauge 1, or
wirelessly transmitting signals indicative of the checked dimension
to a processing and display unit shown in simplified way in FIG. 1
and marked with the reference number 13. Near the push button 3
there is a LED indicator showing the state of the gauge 1 and/or
the function selected by the push button 3.
[0024] A probe 6 is connected to the handle 2--by means of a
coupling mechanism 5 that will be hereinafter described in more
detail--and includes a mechanical armset 7, which is per se known
and only partly visible in FIGS. 1, 3 and 4, consisting of, for
example, two arm assemblies 8, 8' provided each with fulcrum areas
9 lying on parallel axes and carrying respective movable feelers 10
aimed to touch the surface of a cylindrical hole to be checked at
diametrically opposed positions. The free ends of the arm
assemblies 8 and 8' are visible in FIG. 1, while the sections of
FIGS. 3 and 4 only show part of the arm assembly 8 and two of the
respective fulcrum areas 9. Only one movable feeler 10 is
schematically shown in FIGS. 2 and 4.
[0025] The probe 6 further includes a support assembly 11, with
mutually coupled components 11A and 11B, the former carrying the
mechanical armset 7 and the latter defining a substantially
cylindrical clamping surface 12. A centering nosepiece 14 is fixed
to the support assembly 11 of the probe 6, and its end can be
closed by a protecting cap not illustrated for the sake of clarity.
The arm assemblies 8, 8' of the mechanical armset 7 include
suitably sloping abutment surfaces 16 (per se known and only partly
visible in FIGS. 3 and 4) and define a transmission system of a
transmission mechanism that comprises a stem 17, too. The stem 17
can axially slide, guided by a guide bushing 18 connected to the
support assembly 11, and has a substantially ball shaped end 20
which keeps the contact with the abutment surfaces 16 thanks to the
thrust applied by a spring 19. The opposite end 21 of the stem 17
is free and has a substantially plane surface.
[0026] A position transducer 25 having a stationary part and a
movable part is housed in the handle 2 of the plug gauge 1. The
position transducer 25 is for example of the inductive type, and
the stationary part includes windings 26, while the movable part
consists of a magnetic core 24 movable inside the windings 26 along
a longitudinal direction (for the sake of simplicity, in FIGS. 3
and 4 the windings, per se known, are not explicitly drawn and the
reference number 26 actually marks the seat housing these
windings). A bearing and guide element 27 is fixed inside the
handle 2 and defines a housing for the windings 26. A movable
support element 28 carries the magnetic core 24 by means of a rod
29 and includes a hollow enlarged portion having an internal
substantially cylindrical surface 30. The bearing and guide element
27 defines an external substantially cylindrical guide surface 32
that cooperates with the internal surface 30 for guiding the
longitudinal movements of the movable support element 28. A contact
element 33 having a substantially ball shaped free surface is
connected to the movable support element 28 in such a way to be
longitudinally adjustable, while a compression spring 35 acts
between the bearing and guide element 27 and the movable support
element 28 by applying to the latter a longitudinal thrust toward
the outside of the handle 2.
[0027] A wireless transmission system, for example of the
radio-frequency type, is housed in the handle 2 and is electrically
connected to the transducer 25. The reference number 15 in FIG. 3
marks in a schematic way such transmission system and other
electronic devices comprising electronic circuits for processing
electrical measuring signals provided by the position transducer
25, electronic circuits for handling the push button 3 and the LED
indicator 4, and electronic circuits for handling the power supply
provided by one or more batteries 23 housed in the central part of
the handle 2. According to a preferred embodiment of the invention,
the wireless transmission system enables to emit radio-frequency
signals by means of an antenna located inside the handle 2 and
marked with the reference number 22 in FIG. 3. In substance, the
handle 2 includes all the electrical/electronic components,
including the position transducer 25 and the circuits enabling the
power supply and the signal transmission, while the probe 6 only
includes mechanical components, as the mechanical armset 7 and the
transmission mechanism with the stem 17.
[0028] As previously stated, the probe 6 is connected to the handle
2 by means of a coupling mechanism 5 enabling a mutual location and
a quick fastening.
[0029] The coupling mechanism 5 substantially includes three
elements that are visible in FIGS. 3 and 4 in the assembled plug
gauge and are shown disassembled in FIGS. 2 and 5. The three
elements are: a base component 40, an intermediate element 50 and a
clamping element or threaded ring nut 60.
[0030] The base component 40 has a substantially cylindrical,
tubular main portion 41 and a fastening flange 42 that is joined to
an open end of the handle 2 by means of screws. Suitable radial
limiting surfaces, marked with the reference number 43 in FIG. 4,
define the position of the base component 40 so that the latter is
centered with respect to the longitudinal axis of the handle 2. The
internal surface of the base component 40 defines substantially
cylindrical areas and an internal sloping surface 44 diverging
toward a free end of the main portion 41 that has in particular a
truncated cone shape, while at such free end an external threaded
surface 45 is defined. The intermediate element 50 has a particular
tubular shape with variable section clearly visible in FIGS. 2 and
5, and is provided with an annular portion 51 and locking portions
52 that define external sloping surfaces 53, the envelope of which
has a truncated cone shape.
[0031] More specifically, the locking portions 52 are integrally
connected to the annular portion 51 at deformable, reduced
thickness areas 54, are circularly adjacent and define internal
sectors with cylindrical surface and external sloping surfaces 53,
i.e. sectors with sloping surface, having in particular a truncated
cone shape. The free ends of the locking portions 52 define
portions of a circular, radially projecting edge 55. Moreover, the
intermediate element 50 defines a transversal reference surface 57,
the latter lying inside the intermediate element 50 at the annular
portion 51.
[0032] The intermediate element 50 is coaxially arranged inside the
base component 40 in such a way that the sectors with sloping
surface defined by the locking portions 52 contact the internal
sloping surface 44.
[0033] The threaded ring nut 60 defines an internal circular groove
61 and has an internal threaded portion 62 that is coupled to the
external threaded surface 45 of the base component 40. The circular
edge 55 defined by the ends of the locking portions 52 is housed
into the circular groove 61, and the threaded ring nut 60, which is
screwed to the base component 40, applies to the intermediate
element 50 a thrust along the longitudinal axis.
[0034] When the probe 6 is going to be connected to the handle 2,
the elements of the coupling mechanism 5 are coupled in the above
described way and the threaded ring nut 60 is only partly screwed
to the base component 40, the intermediate element 50 being
disposed between the former and the latter. The probe 6 is inserted
into the central opening of the coupling mechanism 5 until
reference surfaces of the probe 6, more specifically a transversal
end surface of the support assembly 11 (more specifically of
component 11B) abuts against the transversal reference surface 57
defined inside the intermediate element 50. Once the suitable
angular position of the probe 6 about the longitudinal axis is
manually determined, the locking is implemented by acting on the
threaded ring nut 60 so that the latter is further screwed to the
base component 40. In this way, further to the longitudinal thrust
applied by the threaded ring nut 60 aiming to push the intermediate
element 50 into the opening of the base component 40, the action of
the internal sloping surface 44 on the external sloping surfaces 53
causes centripetal displacements of the locking portions 52 that
change their radial arrangement owing to the deformation of the
reduced thickness areas 54. Further to these displacements, the
locking surfaces 52 close on the clamping surface 12 defined by the
support assembly 11, and this enables not only to implement the
coupling between the probe 6 and the handle 2, but also to lock
such coupling.
[0035] It should be noted that the deformable locking portions 52
can be implemented in a different way with respect to what is shown
in the figures, for example by using portions with substantially
constant section that can intrinsically deform thanks to a
particular shape or the choice of materials or other reasons.
[0036] When the probe 6 is connected to the handle 2 in the
suitably defined position, the movable support element 28 of the
transducer 25 and the stem 17 are aligned along the longitudinal
axis, and in particular the contact element 33 is urged by the
compression spring 35 against the free end 21 of the stem 17.
[0037] During the checking operations, for example for checking the
diametral dimensions of a hole, transversal movements of the
feelers 10 (or just of one of them) are transmitted by means of the
transmission system, which features the sloping abutment surfaces
16 and the ball shaped end 20 of the stem 17, to the stem 17 that
transmits, in turn, longitudinal displacements to the movable
support element 28 and thus to the core 24 translating among the
windings 26. Electrical signals that are consequently generated by
the transducer 25 and that are indicative of the diametral
dimensions to be checked are transmitted by the plug gauge 1 to the
display and processing unit 13 by means of the wireless
transmission system provided with the antenna 22. The probe 6 that
only includes, as previously stated, simple mechanical component
parts can be rapidly removed by unloosing the screw of the thread
ring nut 60 and easily replaced by a probe 6 with different
dimensions and/or shape in order to check a piece with different
characteristics, such as a piece with a hole with a different
nominal diameter, or to carry out a different kind of checking.
FIGS. 6A, 6B and 6C show examples of different probes that, in a
gauge according to the present invention, can alternatively be
connected to the handle 2 by means of the coupling mechanism 5.
[0038] More specifically, FIG. 6A shows a gauge 6' that is adapted
to check external diameters of mechanical parts and includes a
support assembly 11' and a per-se known mechanical armset 7'
carrying a couple of feelers 10', with a transmission system
comprising a stem 17'.
[0039] FIG. 6B shows a gauge 6'' that is adapted to check internal
diametral dimensions of transversally arranged holes and includes a
support assembly 11'' and a per-se known mechanical armset 7''
carrying a couple of feelers 10'' (only one of them is shown in the
figure), with a transmission system comprising a stem 17''.
[0040] FIG. 6C shows a gauge 6''' that is adapted to check
distances along a longitudinal direction and includes a support
assembly 11''' and a per-se known mechanical armset 7''' carrying
an axial feeler 10''', with a very simple transmission system
comprising a stem 17'''.
[0041] Even in case of breakage of parts of the probe 6, the
replacement can be easily carried out, and in any case the position
transducer has not to be replaced or removed.
[0042] Moreover, the use of the disclosed position transducer 25,
including the particular bearing and guide element 27 and movable
support element 28, provides remarkable advantages especially in
terms of compactness, by ensuring a relatively wide measuring range
with limited longitudinal overall dimensions.
[0043] A gauge according to the invention also enables to use
position transducers of a different type, for example inductive
transducers including guide surfaces that are longitudinally
aligned and placed at a distance from the magnetic core, or
transducers of other types including, for example, optical
devices.
[0044] The hereinbefore described gauge can be modified without
departing from the scope of the present invention.
[0045] The coupling mechanism between the probe and the handle is
hereinbefore described with reference to a manual plug gauge (FIGS.
1 to 5) of the electric type with a wireless transmission for
checking internal diametral dimensions, but it can also be used in
plug gauges or gauges of different types. It can be employed, for
example, in gauges that are aimed to check external diameters or
form deviations, or are provided with mechanical transmission
and/or cable transmission. It can also be automatically employed in
mechanical arms or machine tools. Moreover, it is possible to use
probes for concurrently checking more than one section of a same
mechanical piece including one or more armsets with parallelogram
cells, or fulcrum cells. Checking apparatuses differing from
gauges, for example including checking devices that can provide
information relating to absolute dimensions of the pieces to be
checked, fall within the scope of the present invention, too.
* * * * *